Virus Transmission via Semen

"Establishment of latent infection in the male reproductive tract and virus shedding in semen is probably more common than currently considered."

"An improved understanding of the role of semen in virus transmission is of great value for public health, most notably in the response to outbreaks of high-consequence viral pathogens."

Caitlin Pley, researcher, Charite Center for Global Health, Berlin

 

Published a week ago in the medical science journal Lancet Microbe, an analysis of data extracted from hundreds of studies saw 22 viruses identified with the capability of persisting in human semen; nine of which gave evidence of sexual transmission. It has been understood for decades by scientists that chronic infection-causing viruses such as HIV and herpes are able to persist in semen. Ebola and Zika viruses have more recently been found to infect the male reproductive tract; capable of spreading long after the acute phase of infection, after evading the immune system.

The research, conducted in Berlin by researchers at the Charite Center for Global Health, highlights other potential sources of reproductive complications, underscoring emerging challenges in the development of vaccines and antiviral treatments to oppose these pathogens. Marburg, Mpox and West Nile are among the viruses the study detected in semen, known or suspected capable of sexual transmission. As yet there is no evidence that would support the presence of Crimean-Congo hemorrhagic fever or hepatitis A in semen, despite that both may still be sexually transmissible.

On the other hand, SARS-CoV-02, the virus that causes COVID-19, has been found in male reproductive tissues like the testis and prostate, yet not shown to transmit through sexual contact according to the study. Significant variability in how long viruses can persist in semen was also revealed. Men with weakened immune systems tend to experience, for example, longer viral persistence. Viruses such as West Nile and dengue remain detectable in semen for three to five weeks, in contrast to Ebola and Zika which are known to persist for over two years.